Headers and emission pump
Thread Starter
3rd Gear
Joined: Apr 2013
Posts: 3
Likes: 0
Headers and emission pump
I have an 85 and I'm looking to add inexpensive mods to get a little more HP without spending a lot of cash. I already have an KNN high flow air filter and a high flow Cat back exhaust and it runs very well. I was wondering if anyone out there has replaced the factory shorty headers with long tubes and removed the smog pump and all smog plumbing and had good success with it. I have a friend that did it and it never ran well after that. I'm not sure if he just did something wrong or the computer just cant compensate for those changes. Has anyone done this successfully? If so, does it make enough difference to make it worth doing?
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
I just finished installing some Hedman headers (#68448) on my 87. I had previously removed the AIR system. The car also has true dual exhaust with an X-pipe located just past where the main cat was located.
Removal of the AIR system will not set any codes. You will need a shorter serpentine belt (about 2" shorter). The EGR tube can simply be disconnected and capped; I used a small piece of aluminum strap and re-used the gasket. No code here either.
Are you keeping the main cat? The back half of the factory
Y-pipe can be used to connect the headers. A muffler shop can do this easily.
The stock starter will be a PITA to deal with when installing the headers. With the passenger side header bolted in place, the OEM starter won't fit between the tubes and the block. I wound up buying a Hitachi-style mini-starter from Summit Racing. They have one for about $100 that bolts in and uses the stock wiring. It's about 10 pounds lighter too
I found the biggest performance gain was in mid-range RPM (2000-3500). The car definitely pulls harder. But my '87 has other mods; bored .030 over for 355 CID, ZZ4 cam, intake runners are port-matched, balanced and blueprinted and a light flywheel.
The dual exhaust by itself made a difference and the headers helped even more.
Removal of the AIR system will not set any codes. You will need a shorter serpentine belt (about 2" shorter). The EGR tube can simply be disconnected and capped; I used a small piece of aluminum strap and re-used the gasket. No code here either.
Are you keeping the main cat? The back half of the factory
Y-pipe can be used to connect the headers. A muffler shop can do this easily.
The stock starter will be a PITA to deal with when installing the headers. With the passenger side header bolted in place, the OEM starter won't fit between the tubes and the block. I wound up buying a Hitachi-style mini-starter from Summit Racing. They have one for about $100 that bolts in and uses the stock wiring. It's about 10 pounds lighter too
I found the biggest performance gain was in mid-range RPM (2000-3500). The car definitely pulls harder. But my '87 has other mods; bored .030 over for 355 CID, ZZ4 cam, intake runners are port-matched, balanced and blueprinted and a light flywheel.
The dual exhaust by itself made a difference and the headers helped even more.
Thread Starter
3rd Gear
Joined: Apr 2013
Posts: 3
Likes: 0
Thanks for the feedback! I think I will start with removing the emission pump since the bearings are getting loud anyway. The exhaust is not a true duel exhaust but it does have a newer high flow cat. Headers will be next, thanks for the heads up regarding the starter. Good to know ahead of time.
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
I can understand removing the AIR system. It just pumps air into the exhaust to burn any unburned fuel. However, I would always choose to keep EGR if possible. The 85 can be left in place because of the cast iron head, and it improves mileage and only operates in off the throttle situations. A code 32 will also be set unless you have it programmed out. It will only set an SES light when the ECM calls for it and it doesn't function, but it will store a code.
Last edited by MrWillys; Aug 4, 2013 at 09:52 AM.
Safety Car
Joined: Nov 2009
Posts: 3,973
Likes: 341
From: Adelaide South Australia
I have Hedmans on my 85, I originally had the stock starter in and it fitted ok, have since moved to a mini starter but that was because of the bigger flexplate, the mini starter does give a bit of extra room - its tight in there,
the biggest problem with the longtube headers is the o2 sensor, its now a long way down compared to its original position, it set off my SES light forever, I even put a heated o2 sensor in but it didnt fix the problem, the car runs fine when its warmed up tho,
the hedmans dont come with an o2 bung so you need to weld one in, just something to keep in mind when buying headers,
the biggest problem with the longtube headers is the o2 sensor, its now a long way down compared to its original position, it set off my SES light forever, I even put a heated o2 sensor in but it didnt fix the problem, the car runs fine when its warmed up tho,
the hedmans dont come with an o2 bung so you need to weld one in, just something to keep in mind when buying headers,
Drifting
Joined: Feb 2006
Posts: 1,423
Likes: 96
From: Magnolia Tx
I have the Heddman's on my '86. I put the O2 sensor in the passenger side collector (clutch slave issues) but i have not got an SES light related to O2 in 1000 miles of mixed use. I do get the EGR code on every highway trip. Don't let these minor issues stop you, it is worth it.
